mouthpiece cup shape

I use my hand to put a golf ball in my pocket ... after I or my caddy retrieve it from the hole. Now can you manipulate the golf ball between your 4 fingers as an exercise. I use to be able to, but can't now. Last year sold a dozen brand new balls for $5.00 at my yard sale. Sold my golf clubs in 1980 for $300.00 via a newspaper ad.

As to cup shape, I have a light tongue (OK, K.T. don't touch this!) and find the "C" shape works best for me. Sometimes orchestral music requires a really percussive or slashing attack. The "V" shape is more forgiving for multiple tonguing, smoothing out the T's and K's.

I do use a Sears mouthpiece, totally flat rim, deep "V" on my old Holton cornet. It knows the old tunes.

As I'm not you, have not seen you or heard you play it's difficult to say, but generally they require an itty bitty more air and IMO have a tiny bit warmer intonation and are more in the middle of high and lower notes. This is what the 4 6th grade boys in their second year on trumpet use and what I use to demonstrate to them. Too, I carry one in my pocket all the time to use in evaluating a trumpet I encounter and to use with a David O'Neill Buzzmaster (Warburton) to exercise with when a trumpet isn't practical. Especially, in a cold climate this time of year, all of us are using Kelly Lexan mouthpieces which may seem flatter to some. Overall, a 5c just allows you to flex your lip and facial muscles from time to time. Yes, year 'round it is a Kelly in my pocket so that I'm not walking lopsided with the weight of a Bach ... I have enough difficulty walking now with age and health. As I also play other instruments and "strange" trumpet mouthpieces, I encounter no difficulty playing any or as some would say, I "make do" with what I have, but the switcheroo keeps me versatile ... I believe.